WaterNotes

20: One year

Its so hard to believe its been a year since I started this tank up. It has gone through so many ups and downs and tangential adventures since I first messed about with the substrate over a year ago. There were seahorses, then no seahorses, two species of Halophila flowers, rampant growth of Halodule then a veritable die off, worms invasions, dinoflagellate blooms and plenty of nutrient dosing, water changes and all manner of other husbandry. It sounds exhausting to me now, looking back!

Last month I reported the greenwater outbreak that occurred quite likely alongside my injecting of CO2 at night. It took a solid two weeks to really have the greenwater come down from the pea-soup level it had been at. By this time, a large section of the shoal grass bed had died back, most likely from a lack of proper light levels and perhaps competition for nutrients with the phytoplankton bloom. It was a mess! However, a good smattering of plants survived and I spent a solid weekend cleaning out the tank of old root and rhizome sections and material, shipping off extra healthy plants, and transplanting the remaining sections.

Stargrass cultures that I’ve had growing in a rather low light prop tank were also added.

I also took the opportunity to clean out small areas of the sand bed and lay down new mud material from the Indian River Lagoon in Florida to jump start the bed for the year to come. I’m not sure if that’s something everyone should do, but I figured I might as well when I had the chance. I think I took out about 5 pounds of aragonite and replaced it with at least the same amount of IRL mud.

On a quick trip to Florida this last week, I spent a few hours in the water. The characteristics of the grass beds in several of the places I usually casually survey have changed. Acanthophora macroalgae is growing in a very large bloom over top of shoal grass in many places. And, for the first time, I’ve seen Ruppia maritima (see here) in the lagoon at the northern end. Its a freshwater plant with a high tolerance for salinity, and it may be that the lagoon is running a bit less salty this year. Which is odd, as central Florida is more than a little behind on rain in this region.

Widgeon grass, as its called, is similar to shoal grass (Halodule) but has pointed leaf tips and leafs that are arranged in several whorls going up the main stem. Shoal grass leaves grow only from the base of the plant at the root, with no aerial leaf whorls. I didnt bring any of it back for the tank though, I confess I’m not really sold on its beauty. It may be more a matter of personal taste, I’m sure.

I also located two very large areas covered in Halophila engelmanni that had not existed in the last two years that I’ve been paying attention. Stargrass is usually reported from deeper water, past the Thalassia line in the lagoon, but these plants were in possibly five feet of water, and quite happy in their surroundings. I’d estimate the bed was at least ten yards in circumfrence, with extremely dense plants. I did not find any Halophila decipiens this time around though.

The Halophila ovalis is limping along, a few very small leaf pairs and still kciking about the tank and throwing new pairs about once a week. They are still extremely stunted compared to the original material’s size, but patience seems to be the name of the game. If they can just fuel up enough energy, I’m sure larger and healthier plants are in the future.

CO2 dosing continues, though is religiously turned off at night by shutting off the powerhead used for injection, via a light timer. A very simple and fuss proof system that has ensured no further green water outbreaks. I’ve also rigged a drip line for nitrate dosing, to make my life a bit simpler.

I removed all the remaining Thalassia plants this past week as well. After a year in cpaptivity these plants, while they arrived in wonderful shape, slowly dwindled in leaf size and shape and rhizome weight. It seems that they never really took hold and transplanted. I’m hoping to obtain plants that can be transported with more of their native bed mud material in the future to see if this helps my problems with Thalassia growth. Those rhizosphere microbes might be accounting for some of my failure at culturing these large graceful plants afterall, and native mud would help to ensure more of the microbe population survives.

In all, the tank looks incredibly different than it did a few weeks ago at the last update, but I feel the temporary setback is a good thing. I’m reasonably sure the worms and greenwater wont be returning anytime soon, which will allow me once again to focus on plant health and get things moving along. And really, with the effects of CO2 I’ve seen, I’m hoping it will be a short recovery time till the tank is once more a forest of shoal grass.